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doanthikieulananh
2 năm trước
Hai gương phẳng G1 và G2 quay mặt phản xạ vào nhau. Tia sáng tới xy được chiếu vào gương G1 lần lượt phản xạ trên gương G1 và gương G2. Biết góc tới trên gương G1 là 30 độ. Tìm góc ∝ bởi 2 gương để tia tới trên gương G1 và tia phản xạ trên gương G2 vuông góc với nhau. *Không cần vẽ hình*
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Đề bài dịch bài bên dưới và viết ra 10 cụm động từ trong bài Environmental Pollution Pollution is the introduction of contaminants into the environment that cause harm or discomfort to humans or other living organisms, or that damage the environment, which can come in the form of chemical substances, or energy such as noise, heat or light. Pollutants can be naturally occurring substances or energies, but are considered contaminants when in excess of natural levels. Environmental pollution takes place when the environment cannot process and neutralize harmful by-products of human activities (poisonous gas emissions) in due course without any structural or functional damage to its system. Pollution occurs, on the one hand, because the natural environment does not know how to decompose the unnaturally generated elements (i.e., anthropogenic pollutants), and, on the other, there is a lack of knowledge on the part of humans on how to decompose these pollutants artificially. It may last many years during which the nature will attempt to decompose the pollutants; in one of the worst cases – that of radioactive pollutants – it may take as long as thousands of years for the decomposition of such pollutants to be completed. Why does pollution matter? It matters first and for most because it has negative impacts on crucial environmental services such as provision of clean air and clean water without which life on Earth as we know it would not exist. People are the reason we have pollution. Pollution affects our environment because the water pollution can affect the living conditions of people and plants. Pollution can cause our environment to start and fall. If we don’t have clean water for plants and trees how are we going to make paper and grow veggies for people to eat? This is why the big idea affects the environment and people are the main cause of pollution. Types of environmental pollution Generally speaking, there are many types of environmental pollution, but the most important ones are: • Air pollution - some of the most notable are sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, volatile organic compounds and airborne particles, with radioactive pollutants probably among the most destructive ones (specifically when produced by nuclear explosions) • Water pollution - includes insecticides and herbicides, food processing waste, pollutants from livestock operations, volatile organic compounds, heavy metals, chemical waste and others • Soil pollution (contamination) - hydrocarbons, solvents and heavy metals In modern industrialized societies, fossil fuels (oil, gas, coal) transcended virtually all imaginable barriers and firmly established themselves in our everyday lives. Not only do we use fossil fuels for our obvious everyday needs (such as filling a car), as well as in the power-generating industry, they (specifically oil) are also present in such products as all sorts of plastics, solvents, detergents, asphalt, lubricating oils and in a wide range of chemicals for industrial use. Among other pollution sources, agriculture (livestock farming) is worth mentioning as the largest generator of ammonia emissions resulting in air pollution. Of the total amount of greenhouse gasses, in agricultural production occurs about 30%. Thereof agricultural soil produce 32%, livestock 31%, crops cultivation 12%, from manure management occur 6% and 19% of other emissions. Environmental pollution is causing a lot of distress not only to humans but also animals, driving many animal species to endangerment and even extinction. The trans boundary nature of environmental pollution makes it even more difficult to manage it. It’s widely recognized that we are hugely overspending our current budget of natural resources – at the existing rates of its exploitation, there is no way for the environment to recover in good time and continue “performing” well in the future. Everything on our planet is interconnected and while the nature supplies us with valuable environmental services without which we cannot exist, we all depend on each other’s actions and the way we treat natural resources MN GIẢI GIÚP EM VS Ạ

II. Finish each of the following sentences in such a way that it is as similar as possible in meaning to the sentence printed before it. Do not change the form of the given word. (5 pts) 86. Why didn't you ask me before you used my laptop? (RATHER) ……………………………………………………………………………………. 87. Mary hasn't been feeling well lately. (RUN) ……………………………………………………………………………………. 88. Tony should have been given more time to complete his thesis. (INSUFFICIENT) ……………………………………………………………………………………… 89. "I don't approve of people who tell lies, said Jack. (EXPRESSED) ……………………………………………………………………………………… 90. She was unable to solve the problem alone. (BE) ………………………………………………………………………………………

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